Combined bulldozer and tractor shovel



Nov. 21, 1950 R. L WELLS 2,530,414

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Patented Nov. 21, 1950 COMBINED BULLDOZER AND TRACTOR SHOVEL Robert L.Wells, Douglas, Ga., assignor to Bucyrus-Erie Company, South Milwaukee,Wis., a corporation of Delaware Application May 19, 1948, Serial No.27,993

2 Claims. Cl. 214-140) My invention relates to new and usefulimprovements in tractor-mounted material-handling implements, moreparticularly to tractor shovels modified to both push, as well as carrydirt.

In a machine of the type to which my invention is more particularlyadapted, the implement is usually designed for attachment to aconventional tractor and consists of a transverse bucket, two armspivoted on the tractor for pushing and lifting the bucket, and means toraise and lower the arms. The last-mentioned means usually consists ofone or two hydraulic cylinders actuated by a pump driven by the engineof the tractor. The bottom of the bucket is usually concave toward thefront in vertical cross-section, the ends being closed by fiat plates.

In the past, tractor shovels have been converted to bulldozers (l) bysubstituting a separate bulldozer blade for the bucket, or (2) byholding the bucket in dumping position, preferably with an hydraulicdump control (see for example U. S. Patent No. 2,413,097, issued toBarker, December 24, 1946), and bulldozers have been converted totractor shovels (3) by hinging 'the bulldozer moldboard along atransverse axis adjacent the digging edge of the blade and swinging themoldboard back to recumbentposition when it is desired to carry dirt(see U. S. Patent No. 2,303,379, issued December 1, 1942, to G. W.Mark).

These methods have serious drawbacks. The.

bulldozing, projecting side plates, and overhang on the push arms. Thethird method eliminates the above objections, but introduces newdifliculties in that the narrow sideplates of a bulldozer moldboard areinadequate to contain the dirt when the moldboard is used as abucket,and that the fixed pitch of the bottom edge, although suitable fordozing, is improper for digging.

Accordingly it is the principal object of my invention to provide asimple and inexpensive combination bulldozer and tractor shovel thatwill have all of the advantages and none of the disadvantages of theprior art.

In addition to my principal object, above stated, I have worked out anumber of novel and useful details, which will be readily evident as thedescription progresses.

My invention consists in the novel parts and in the combination andarrangement thereof, which are defined in the appended claims, and ofwhich one embodiment is exemplified in the accompanying drawings, whichis hereinafter particularly described and explained.

Throughout the description, the same reference number is applied to thesame member or to similar members.

Figure l is a side elevation of a, tractor and combined bulldozer andtractor shovel embodying my invention.

Figure 2 is a plan view of this same tractor and combined bulldozer andtractor shovel.

Figure 3 is anenlarged side elevation partly in section, showing thebucket and associated parts of my invention, in pushing position as abulldozer.-

Figure 4 is similar to Figure 3, but with the bucket shown in diggingposition as a tractor shovel.

Referring now to Figures 1 and 2, we see that H is a conventionaltractor, mounted on creeping traction units l2, which are pivoted onpropelling shaft [3 and have considerable freedom to oscillateindependently about said shaft to conform to uneveness of the ground.

Pivoted to eachside of cradle frame I4 on the tractor as at rearwardpoint I5 is a forwardly projecting push arm l6. These arms are connectedat their front end by cross beam lid, and serve to support and impelbucket I'I. They are raised and lowered by the following describedmechanism. To an intermediate point It on each arm I6 there is pivotedan hydraulic cylinder-piston assembly I9 which is also pivotallysupported at a rearward and relatively low point 20 on the cradle frameI. The two cylinders are interconnected and their pistons are actuatedby pressure fluid supplied from a conventional hydraulic unit 2| at thefront of the tractor.

We now come to the inventive features of my invention, on which seeprimarily Figures 3 and 4.

Turning to Figures 3 and 4, we see that bucket ll comprises bottom plate22, and side plates 23.

Bucket side plates 23 are rigidly carried at the ends of cross beam liaby push arms I, and

serve as closures for the ends of the bucket. Push arms l6 and sideplates 23 together will sometimes be referred to herein collectively aspush means," but other push means could be used without departing fromthe spirit of my invention.

Bottom plate 22 has along its lower end a digging edge 25 and is hingedto the forward end of side plates 23 for fore-and-aft movement about atransverse axis 28 adjacent digging edge 2!. On the back of bottom plate22 are brackets 21, for resting engagement with rests 28 on cross 3 beamIla when the bottom plate is in carrying position. n the back of bottomplate 22 are several vertical reinforcing ribs 20, and at the ends ofthe bottom plate are cutting shoes 3. for

.use when the bottom plate is raised in dirt-pushing position (Figure 3)On each arm I is mounted an hydraulic cylinder ii, the piston 32 ofwhich is pivotally connected through sliding link 33 and pivot link 24to one or more ribs 2!. This cylinder II is preferably double-acting,pressure fluid therefor being supplied from hydraulic unit 2|, thedetails of which are conventional and form no part of my invention.

My invention operates as follows. When push arms II are lowered andpistons 12 are extended, bottom plate 22 is in vertical dirt-pushingposition, as shown in full lines in Figure 3, and the machine operatesas a bulldozer. It will be noted that when the bottom plate 22 is inthis position, its digging edge 2! has the proper steep inclination forbulldozing and that side plates 23 do not project in front ofcutting-shoes 32. When pistons 32 are retracted so that bottom plate 22is recumbent in dirt-carrying position, as shown in Figure 4, themachine operates as a tractor shovel, digging edge 2! now being properlynearly horizontal, and side plates 22 now forming a substantial dirtenclosure with the bottom plate 22. Bucket l1 and push arms I! can beraised by extending cylinder-piston assemblies l0, and then the bucketcan be dumped by extending pistons 32 so that bottom plate 22 ejects theload forwardly from the bucket.

Having now described and illustrated one form of my invention, I wish itto be understood that my invention is not to be limited to the specificform or arrangement of parts herein described and shown.

I claim:

1. In a material-handling implement for attachment to a tractor, thecombination of: push means attachable to the tractor, and includinglongitudinal side plates as a rigid part thereof; means, supportable bythe tractor, for raising and lowering the push means; a transversebottom plate, pivotally supported adjacent its for-- ward edge by thepush means, the side plates serving as closures for the ends of thebottom plate, to form therewith a dirt-holding bucket when the bottomplate is in recumbent dirt-carrying position; and power-operated meansto swing the bottom plate from recumbent dirt-carrying position toupright dirt-pushing position.

2. A material-handling implement according to claim 1, furthercharacterized by the fact that the bottom plate is concave forwardly,and has a transverse digging edge rigid with and swingable with thebottom plate.

3. A material-handling implement according to claim 2, furthercharacterized by the fact that Y the bottom plate is pivoted on the sideplates, adjacent their forward edges.

ROBERT L. WELLS.

REFERENCES CITED The following references are of record in the tile ofthis patent:

UNITED STATES PATENTS Number Name bate 1,690,886 Crombie, Jr. Nov. 6,1928 2,303,379 Mork Dec. 1, 1942 FOREIGN PATENTS Number Country Date458,589 Great Britain Nov. '12, 1936

